Influence of surface oxidation of titanium on adhesion.
OBJECTIVE
The adhesive bonding of titanium was investigated using a methacrylate-phosphate primer and a luting agent. The present study investigates the influence of heat oxidation as well as a suitable durable bonding method for treating the surface of titanium.


METHODS
Two groups of disc specimens were fabricated by milling and casting, respectively. Machine-milled specimens were subjected to heat treatment, and three groups of cast metal specimens underwent following respective treatments: (1) as-cast, (2) emery-polishing, (3) alumina-blasting after emery-polishing. The primer contained 10-methacryloyloxydecyl dihydrogen phosphate (MDP); the luting agent was based on methyl methacrylate (MMA), and was initiated with tri-n-butylborane derivative (TBB). Each specimen was primed and bonded to an acrylic rod. Shear bond strengths were determined before and after thermocycling.


RESULTS
The mean bond strength of the machine-milled emery-polished group was 32.5 MPa after 5000 thermocycles with only a slight decrease in bond strength. A decrease in the bond strength occurred when the heat-treatment temperature was above 400 degrees C. Although both emery-polishing and alumina-blasting were effective, the minimum decrease in bond strength was obtained with alumina-blasting.


CONCLUSIONS
The excess surface oxide layer may be of great concern as a possible cause of decreased bonding durability. Sufficient bonding durability for clinical use was obtained when the titanium was alumina-blasted.
Taira
Y
Y
Department of Fixed Prosthodontics, Nagasaki University School of Dentistry, Japan.
Matsumura
H
H
Yoshida
K
K
Tanaka
T
T
Atsuta
M
M
D000268:Adhesiveness; D000537:Aluminum Oxide; D001896:Boron Compounds / Q000737:chemistry; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry; D003735:Dental Casting Technique; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D006358:Hot Temperature; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate; D008768:Methylmethacrylates / Q000737:chemistry; D010084:Oxidation-Reduction; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013674:Technology, Dental; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
D001896:Boron Compounds; D003734:Dental Casting Investment; D003738:Dental Cements; D003764:Dental Materials; D008689:Methacrylates; D008768:Methylmethacrylates; D019279:Resin Cements; C009523:tri-n-butylborane; C009495:titanium dioxide; D020366:Methylmethacrylate; C069749:methacryloyloxydecyl dihydrogen phosphate; D014025:Titanium; D000537:Aluminum Oxide